A senior advisor to the government in Scotland has resigned, following two convictions for drink-related motoring offences.

Philip Chalmers, responsible for the presentation of key government policy announcements, is the second aide lost to First Minister Donald Dewar in the last few months, following the sacking of chief of staff John Rafferty.

Mr Chalmers had recently been convicted of two serious motoring offences in the centre of Glasgow.

Philip Chalmers: Tendered resignation

In the first incident he was found guilty of being drunk in charge of a parked motor vehicle. In the second, he was convicted of drinking and driving.

Mr Chalmers, who worked in the strategic communications unit, had reported the first incident to his manager at the time, Mr Rafferty.

He reported the second to Mr Dewar on Monday, when he returned after a period of being absent with flu.

He offered then to resign, but Mr Dewar is understood to have asked him to think about his decision.

Friendship and support

In a letter to Donald Dewar, Mr Chalmers thanked the First Minister for his friendship and support.

He added: "I know better than most just how hard you work for the people of Scotland. It has been an honour and a privilege to work with you during campaigns and in government."

In reply, Mr Dewar said he accepted his resignation with regret.

He said: "I have been tremendously grateful for your hard work, loyalty and skilled commitment in the Labour Party and the Scottish Executive.

"You played a very constructive and notable role. You will remain a firm friend and I hope these problems are soon behind you."

Scottish National Party parliamentary business manager Mike Russell said: "Following on from chief of staff John Rafferty's sacking, this resignation of a second special adviser reduces the Scottish Executive to a shambles.

"To lose one special advisor is a misfortune. To lose two reeks of misjudgment."